The Edelbrock Performer RPM heads are Typically $900-1100. Some of the larger heads can run as much as $1400 each.

I think if they can come to market around 2000-2500 a set assembled they'll sell a good amount. Any more than that and you're out of reach for the average buyer.

I have about $2500 in my Apaches Ray ported. That covers the heads, shipping, porting, PSI 1515ML springs and Manley Ti retainers.